Absorbent articles, such as sanitary napkins, pantiliners, and incontinence pads, are typically worn in the crotch region of an undergarment. These devices are designed to absorb and retain liquids and other discharges from the human body to prevent body and garment soiling. The absorbent articles are typically placed in a garment such as the wearer's panty and worn between the wearer's legs, adjacent to the genital (or fluids discharge source) area of the body. Disposable absorbent articles generally comprise a fluid-permeable topsheet, an absorbent core, and a fluid-impermeable backsheet.
Recently, research has focused on removal of foul odors and prevention of skin diseases. Many bodily fluids tend to have an unpleasant odor (or malodor), or develop such an odor when in contact with air and/or bacteria for prolonged periods. Additionally, urine and/or other exudates absorbed into the absorbent article are converted to ammonia by urease produced by skin-flora, i.e., a group of normal microorganisms on the body. This ammonia, in turn, may cause dermatitis, rash and/or other forms of skin irritation. It is known that such disease of the skin can be a serious medical matter.
Antimicrobial materials and bactericides in general are chemical compositions that are used to prevent microbiological contamination and deterioration of products, materials, and systems. Such antimicrobial materials and bactericides can also effectively work as an odor control material for the removal or reduction of foul odors developed from disposable absorbent articles which has already absorbed body fluids. However, depending on the nature or characteristics of antimicrobial materials or bactericides in disposable absorbent articles, it is found that such antimicrobial materials and bactericides tend to affect skin health. In particular, many of these materials, by having antimicrobial activity, can alter the normal distribution of body flora. Therefore, care must be taken in the selection and use of these materials so as to avoid disrupting the normal flora on the body.
Japanese Patent No. 2938507 discloses a paper diaper which includes, in an absorbent material, a polyphenol organic compound which is selected from a group consisting of a tannin, a tannin acid, a galla rhois, a gallnut, and a gallic acid, which are extracted from plants. The polyphenol organic compound is included in an absorbent material. This publication states that the diaper disclosed provides a good remedy against diaper rash (and thus, a good skin friendliness nature), however, it does not seem to provide enough odor control function which is necessary for paper diapers.
International Publication No. WO 01/03748 discloses a sanitary napkin which includes a galla rhois-containing composition and a herb medicine applied thereto for removal of odor. The sanitary napkin disclosed seems to have odor control function, however, the galla rhois has been reported to generate skin rash, and thus may not be appropriate, in particular for direct exposure to the normally sensitive woman's vulva or vaginal areas.
Thus, there is a need for an absorbent article that has an improved odor control function while maintaining body comfort and body protection against the wearer's body.